New waste regulations spark Scotland’s AD boom

Scotland's anaerobic digestion (AD) industry is set to more than double over the next two years, fuelled by the mandatory separation of food waste for businesses.

According to new figures from Scottish Renewables, 16 AD plants already operate throughout the country and a further 24 have received planning approval.

Scottish Renewables’ policy manager Stephanie Clark said the industry growth can be put down to the country’s new Waste Regulations, which came into effect in January, along with a rise in local authority food waste collections.

“Food waste is a source of fuel for anaerobic digesters, and we expect that an increase in the amount of food waste collected by local authorities will now lead to a significant increase in the number of AD plants in Scotland,” said Clark.

The AD process involves farm slurry, vegetable peelings, paper and other organic material rotting inside a closed chamber to produce gas, which is then used to generate electricity. Participating Scottish local authorities currently pick up 8,000 tonnes of household food waste every year. That figure could rise to 72,000 tonnes if all 32 councils roll out weekly food waste collection schemes.

Scottish Water

One company that has invested heavily in an anaerobic digestion facility is Scotish Water, based in Lanarkshire, which set up its own food waste collection service to fuel its Deerdykes facility.

The facility can generate up to 8,000 Mwh of green electricity each year – enough to power up to 2,000 homes – and is the largest single contributor to Scottish Water’s energy self-generation, at around 32%.

Scottish Water’s finance director Alan Scott said: “Since the launch of our anaerobic digestion facility at Deerdykes in 2010, we have recycled approximately 80,000 tonnes of food waste, transforming it into renewable energy and natural fertiliser.

“To support the new Waste (Scotland) Regulations which came into effect on 1 January 2014, we have also invested in a food waste collection service to collect and recycle food waste from a wide variety of businesses including hotels, restaurants, leisure and entertainment facilities, providing a convenient and flexible solution to customer needs.”

According to data provided by WRAP, there were 32 AD plants in the UK in 2009. Currently, there are around 148 operational sites and 308 AD sites under development, with the industry growing by 39% last year.

Luke Nicholls

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